Can't Shift Into First

[kshafer1]

This is what I run in my '79 SC:

Kendall NS-MP Hypoid Gear Lube AE 80W-90

I made that choice based on the wisdom and advice of a few professional mechanics I trust.

[OsoMoore]

Found this: How-To: Porsche 915 Transmission Repair Tutorial Part 1 - Porsche Wiki

Thanks Peter - I think I will be well-guided.

[OsoMoore]

Big morning!

The engine drop team! Its my first drop, but Arthur is the local expert and always ready to help the uncertain rookie.



The engine is out. She looks a lot bigger out of the car!



The transmission! I spent an hour cleaning dirt and grit off. Three brushes later, it was still pretty bad. So I hooked up the power sprayer. After soaking myself, I did accomplish a good clean. You know you are done when it's you getting the transmission dirty.



The workspace!



The motivational background!

[OsoMoore]

I have the cap off and am ready to take off the big nuts. I read on the other thread:
"The castelated nut and the big nut are sometimes a bear to get off. You can put the transmission into reverse and a forward gear at the same time to lock it. For that you need to use a screwdriver through the access cover and push one of the shift rods until it engages."

I have the access cover off, and can see a selector fork (I think that's what it is) flipping around on its hinge. Any other details on how to do this in-double-gear setup?

[OsoMoore]

Got it! I was pushing upward trying to pop it out of fifth. I had it set vertically.

Pop! Suddenly I realize I'm holding the R/5 fork and the gear has shot up above my head.

Smack! Ouch that kind of hurt.

I picked the gear up off the floor and examined it - no apparent damage. Then I checked my head. Didn't find any blood (although later I discovered a minor ding.)

After getting some help from my brother-in-law, we succeeded in putting her into reverse and 3rd at the same time. We also confirmed that we still can't get into 1st, although we can get into all other gears. Now I just need to remove the Big Nuts of Doom.

[DRACO A5OG]

Use a breaker bar and it will come right off

[OsoMoore]

So what is up with this nut on the main shaft? Part of the nut is bent into the divot in the shaft, and I can't seem to bend it straight with anything.
Should I just put the big socket on and push away, and let the leverage sort it all out?

[Matt Monson]

You need a pretty small punch to bend it back out. Or a small flathead screwdriver you consider disposable. Wear safety glasses.

[DRACO A5OG]

+1 use a sacrificial screw driver or flat head punch/chisel, just take care when doing this, don't mis-hammer to the gear.

[DRACO A5OG]

BTW, did you buy/borrow the required jig to re-assemble the gear box? This plus shift fork alignment is quite necessary to insure everything is properly positioned/seated.

[OsoMoore]

Originally Posted by DRACO A5OG

+1 use a sacrificial screw driver or flat head punch/chisel, just take care when doing this, don't mis-hammer to the gear.

I tried another screwdriver without any luck. I can't find an edge in there to wedge it into. Whoever bent it into place did a great job. I'll see if I can find a good dentist pick too to work it more open.

Originally Posted by DRACO A5OG

BTW, did you buy/borrow the required jig to re-assemble the gear box? This plus shift fork alignment is quite necessary to insure everything is properly positioned/seated.

I have a friend who might have one, he mentioned it a week ago and I don't think he's checked yet.

[john walker's workshop]

impact wrench. don't worry about bending the notch back. never heard of anyone actually doing that. then get a new nut.

[OsoMoore]

Regarding the shift fork jig, it looks like its only $16 from PP (PEL-TOL-SFJ3) so I'll probably just get my own.

Originally Posted by john walker's workshop

impact wrench. don't worry about bending the notch back. never heard of anyone actually doing that. then get a new nut.

Thank you John, I'll just go ahead and impact it.

[DRACO A5OG]

I just used the punch and punched it back for extra measure, PAG must have had a reason to do that in the first place, no? BTW, it takes allot of torque to tighten that nut.

[OsoMoore]

Originally Posted by DRACO A5OG

I just used the punch and punched it back for extra measure, PAG must have had a reason to do that in the first place, no? BTW, it takes allot of torque to tighten that nut.

Yeah, I'm not sure how I will tighten it when I get there. Most torque wrenches I can easily lay hands on max at 150 ft/lbs. I'll find something!

[Mark Salvetti]

Breaker bar and a scale. Stand on the scale, breaker bar on the nut and horizontal around waist level. Measure distance from your grip to the nut. Say it's 2 ft. Press down on the bar and watch the scale. When the scale reads 100 lbs less, you've applied 200 ft-lbs. (100 lbs x 2 ft).

I think the toughest part will be securing the transmission so it doesn't move while you do this.

Mark

[uwanna]

Originally Posted by OsoMoore

Yeah, I'm not sure how I will tighten it when I get there. Most torque wrenches I can easily lay hands on max at 150 ft/lbs. I'll find something!

Go to O'Reilly or Autozone, they will loan you high torque wrench. Q'Reilly handed me a brand new one to use on my 915. They just charge your credit card for full price and refund when you return.

[OsoMoore]

Good idea uwanna! They know me pretty well by now.

My old electric HF impact driver took both bolts off easily. I think this thing may never have been opened, all the bolts came off smoothly and there was no gasket stuff except a thin paper one.

Here's what we found.
This little chunk of metal kept me from removing the gear until I worked it out with needle nose pliers.

I saved this nut for last because it was hard to get to. When I got around to it, I found it was halfway off already. Yikes!


Looks like 4 teeth are missing on the 1st gear (I think this is first - the gear on the 1/2 shaft).



Two issues.
1) I still can't shift it into first even opened this much, although I can hit all the other gears (before I took out the last set of bolts).
2) I can't get the pair of shafts to slide out now that I have the last set of bolts out. The 1/2 shaft seems loose and ready to move, but the 3/4 shaft rocks slightly but seems stuck somehow.

Ideas? Pull harder? I was able to lift the entire housing by holding the two shafts and it didn't come free.

[john walker's workshop]

put it in 3rd gear first. then grab the whole works and wiggle it out of the diff housing. side detents out, of course.

[kodioneill]

That 1st syncro sure looks like it got hot.